SPH Modeling of Wave Transformation over a Coral Reef with Seawall

Abstract

Wave transformations over a coral reef with a steep front slope were comparatively studied using both laboratory tests and smoothed particle hydrodynamic (SPH) modeling. In the numerical model, nonreflective generation and absorption of waves were realized by adding a source term and a velocity attenuation term into the governing momentum equation. The physical and numerical models were carefully designed so that the nonphysical rise of the mean water level over the reef was avoided. Experimental and numerical results on the free surface elevations and the spatial distributions of wave height and wave setup over the reef with and without a vertical seawall were compared and good agreements were obtained. The cross-spectral transfer of wave energy from the peak frequency to the lower and higher frequencies, the vertical distributions of wave-induced current over the reef, and the effects of the seawall position on the maximum wave setup and wave run-up are discussed.